問題描述：
Ubuntu下連接raw.githubusercontent.com失敗
wget https://raw.githubusercontent.com/madmashup/targeted-marketing-predictive-engine/master/banking.csv
--2020-05-17 17:00:19-- https://raw.githubusercontent.com/madmashup/targeted-marketing-predictive-engine/master/banking.csv
Resolving raw.githubusercontent.com (raw.githubusercontent.com)... 0.0.0.0, ::
Connecting to raw.githubusercontent.com (raw.githubusercontent.com)|0.0.0.0|:443... failed: Connection refused.
Connecting to raw.githubusercontent.com (raw.githubusercontent.com)|::|:443... failed: Network is unreachable.
解決方法：
step-1
在 https://site.ip138.com/raw.Githubusercontent.com/
輸入raw.githubusercontent.com查詢IP地址
step-2
修改hosts Ubuntu，CentOS及macOS直接在終端輸入
sudo vi /etc/hosts
添加以下內容保存即可 （IP地址查詢後相應修改，可以ping不同IP的延時 選擇最佳IP地址）
# GitHub Start
52.74.223.119 github.com
192.30.253.119 gist.github.com
54.169.195.247 api.github.com
185.199.111.153 assets-cdn.github.com
151.101.76.133 raw.githubusercontent.com
151.101.108.133 user-images.githubusercontent.com
151.101.76.133 gist.githubusercontent.com
151.101.76.133 cloud.githubusercontent.com
151.101.76.133 camo.githubusercontent.com
151.101.76.133 avatars0.githubusercontent.com
151.101.76.133 avatars1.githubusercontent.com
151.101.76.133 avatars2.githubusercontent.com
151.101.76.133 avatars3.githubusercontent.com
151.101.76.133 avatars4.githubusercontent.com
151.101.76.133 avatars5.githubusercontent.com
151.101.76.133 avatars6.githubusercontent.com
151.101.76.133 avatars7.githubusercontent.com
151.101.76.133 avatars8.githubusercontent.com
# GitHub End